CVE-2026-11979
Published: July 1, 2026Last modified: July 8, 2026
Description
libxml2 is vulnerable to multiple stack-based buffer overflows in the xmlcatalog utility when running in --shell mode. The usershell() function processes user input using fixed-size stack buffers without proper bounds checking. By supplying an overly long input line, an attacker can overflow internal buffers (command, arg, and argv) during input parsing. This results in memory corruption within the stack frame. Successful exploitation may cause a crash or potentially allow arbitrary code execution in the context of the xmlcatalog process. This issue has been fixed in the commit c2e233fc. NOTE: The maintainers of this project did not agree that this issue is a vulnerability and considered it a bug.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | REQUIRED |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
Notes
As per https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1124#note_2785199, this is not considered a security issue: > This is not a security bug. It's a command line option, so it requires the user to call the program with a long crafted arguments. If the "attacker" can do that, he can just call rm -rf *. So this is not a security issue.
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | libxml2 | Not affected (2.10.3-r2) |
| 25 LTS | libxml2 | Not affected (2.13.8-r0) | |
| Stream | libxml2 | Not affected (2.10.3-r2) | |
| Hardened Containers | 23 LTS | libxml2 | Not affected (2.10.3-r2) |
| 25 LTS | libxml2 | Not affected (2.13.8-r0) | |
| Stream | libxml2 | Not affected (2.10.3-r2) |